17 



As a technical remark we must say that we feel it would have been better, 

 notwithstanding a slight increase in the price, to print such a valuable work 

 on better paper. This would also have allowed a much better reproduction 

 of the figures, which are sometimes too much schematized. 



P. D. NIEUWKOOP 



"DEVELOPMENT OF VERTEBRATES" 

 1956 

 by E. Witschi W. B. Saunders Company 



588 pp. with 370 figs Philadelphia, London 



Price: ? 



This textbook of embryology has been written for premedical students and 

 zoology majors who have completed a course in general biology, and intends 

 to show the reader that the process of development is widely open to scientific 

 analysis. 



After some general chapters on spermato- and ovogenesis, fertilization, and 

 cleavage and gastrulation, the development of the amphibians, birds and 

 mammals is treated extensively, using normal stages and stage maps as a 

 basis for comparison, while some separate chapters are devoted to human 

 development. In this textbook a little too much emphasis has been laid on 

 reproduction and the role of the endocrine system, which is, however, something 

 we can easily forgive the author, who has devoted a lifetime to these particular 

 aspects of development. 



Notwithstanding the rather personal character of this textbook, the ap- 

 preciation of which may vary among individual readers, we feel very satisfied 

 as to the synthesis of experimental and descriptive data, which gives the reader 

 a very good insight into the causal relationships which play such an important 

 role in the development of the complexity of the organism. The carefully 

 selected and newly prepared figures illustrate the text in a very pleasant and 

 constructive way. 



We feel, however, rather strong objections against the author's conception 

 of the relationships between ontogeny and phylogeny. A direct comparison 

 of certain developmental stages of higher vertebrates with adult forms of lower 

 groups of animals (called "corresponding ancestors") is too great a simpli- 

 fication and popularization of the highly complex nature of phylogeny as 

 well as development, for this to appear in a scientific textbook of this standard. 



As a purely technical point we should like to suggest that the author should 

 in future editions avoid the combination of figures of different magnification 

 in one text figure, and the insertion of tex figures ino a text in which they do 

 not belong. 



Finally we should like to suggest that the author might, in future editions, 

 insert literature references directly in the text of the various chapters instead 

 of giving a bibliography at the end of the book with reference to corresponding 

 chapters. We fear that otherwise very few students will find the rather difficult 

 way to the original literature. 



P. D. NIEUWKOOP 



